Efficacy and safety of novel topical pigment-correcting regimen with biweekly diamond tip microdermabrasion procedures on facial hyperpigmentation

BACKGROUND

Facial hyperpigmentation can negatively affect an individual's emotional and psychosocial well-being.

AIMS

Assess safety and tolerability of a combination of microdermabrasion (DG) procedures using a novel brightening pro-infusion serum (EC-DG) with a targeted at-home treatment regimen in subjects with mild to severe facial hyperpigmentation, including melasma, post-inflammatory hyperpigmentation, and dark spots.

PATIENTS/METHODS

This 12-week, open-label study enrolled 18 subjects (Fitzpatrick skin types I-IV) who underwent 6 in-office DG procedures with EC-DG (one procedure administered biweekly), along with daily topical application of a brightening treatment serum and dark spot cream. End points included change from baseline across multiple skin quality attributes and the Melasma Area and Severity Index (MASI), self-assessment questionnaires, and tolerability assessments.

RESULTS

The combination treatment was well tolerated and resulted in significant (p ≤ 0.05) improvements from baseline in radiance, tactile roughness, and moisturization/hydration immediately after the first treatment, in MASI score at day 3, and in overall hyperpigmentation at week 4. Most (94.1%) subjects were satisfied with treatment.

CONCLUSIONS

DG procedures using EC-DG combined with a targeted at-home skincare regimen are effective and tolerable for treating facial hyperpigmentation across a broad range of skin types.

The Therapeutic Use of Antioxidants for Melasma

Melasma is a chronic dermatologic condition with an incompletely understood pathogenesis and well-demonstrated impact on patient quality of life. Melasma is a common cause for seeking dermatologic care, and with no universally efficacious therapy or cure, com-bination treatment is the best approach for many cases. Numerous studies have demonstrated the role of oxidative stress in patients with melasma, prompting investigation into several antioxidants for melasma therapy. In this review, we discuss the well-defined role of oxidative stress in melasma and the therapeutic efficacy of various antioxidants for patients suffering from melasma. We focus our discussion on studies investigating the role of vitamin C, azelaic acid, cysteamine, glutathione, carotenoids, and numerous other antioxidants in disorders of hyperpigmentation. There is promising evidence for the use of these antioxidants, as topical, oral, and intra-venous preparations, both in isolation and in conjunction with other melasma therapies. J Drugs Dermatol. 2020;19(8):788-792. doi:10.36849/JDD.2020.5079.

Post-Inflammatory Hyperpigmentation: A Review of Treatment Strategies

Post-inflammatory hyperpigmentation (PIH) is a reactive process resulting from increased melanin or abnormal distribution of melanin secondary to inflammatory skin conditions, dermatologic therapies, and external stimuli. Because PIH is a common condition that has a substantial effect on the quality of life, an understanding of its treatment modalities is essential. Though there are many therapeutic strategies for hyperpigmentary conditions such as melasma that are described in the literature, fewer studies focus on PIH. This article aims to provide a comprehensive literature review of therapies specifically used to treat PIH, such as topical combinations, chemical peels, and lasers. J Drugs Dermatol. 2020;19(8): doi:10.36849/JDD.2020.4887.

Hispanic/Latinos and Skincare: Disparities in Product Development, Marketing, and Toxicity

“Hispanic” and “Latino” (also known as Mestizo) describe a diverse racial and ethnic group, with a range of cultures, languages, and biological ancestry. It includes individuals of Mexican, Central-to-South American, and Spanish-Caribbean (eg, Cuban, Puerto Rican, and Dominican) descent.1 Individuals of Hispanic/Latino race and ethnicity represent a heterogenous group of people with different skin tones and Fitzpatrick phototypes. Hispanic/Latinos are the fastest growing population in the United States (US) - projected to increase from 55 million in 2014 to 119 million in 2060, an increase of 115%.2 By 2060, more than one-quarter (29%) of the US is projected to be Hispanic/Latino.2.

Advances in the Design of Genuine Human Tyrosinase Inhibitors for Targeting Melanogenesis and Related Pigmentations

Human tyrosinase (hsTYR) is the key enzyme ensuring the conversion of l-tyrosine to dopaquinone, thereby initiating melanin synthesis, i.e., melanogenesis. Although the protein has long been familiar, knowledge about its three-dimensional structure and efficient overexpression protocols emerged only recently. Consequently, for decades medicinal chemistry studies aiming at developing skin depigmenting agents relied almost exclusively on biological assays performed using mushroom tyrosinase (abTYR), producing a plethoric literature, often of little useful purpose. Indeed, several recent reports have pointed out spectacular differences in terms of interaction patterns and inhibition values between hsTYR and abTYR, including for widely used standard tyrosinase inhibitors. In this review, we summarize the last developments regarding the potential role of hsTYR in human pathologies, the advances in recombinant expression systems and structural data retrieving, and the pioneer generation of true hsTYR inhibitors. Finally, we present suggestions for the design of future inhibitors of this highly attractive target in pharmacology and dermocosmetics.

Randomized, Double-Blinded, Split-Face Study Comparing the Efficacy and Tolerability of Two Topical Products for Melasma

BACKGROUND

Melasma is a common disorder of hyperpigmentation that disproportionately affects individuals with skin of color. There is a paucity of studies evaluating non-hydroquinone (HQ) topical therapies for the treatment of melasma in darker skin types.

OBJECTIVE

To compare the safety, efficacy, and tolerability of a HQ-free, retinol-free cosmetic topical brightener (CTB) and HQ 4% in the treatment of moderate symmetric facial melasma in patients with Fitzpatrick skin types (FST) III–VI. Methods & Materials: This was a randomized, double-blinded, split-face clinical trial. Eighteen adult patients with facial melasma were treated with CTB and HQ 4%, each to a different side of the face, twice daily for 12 weeks. Clinical assessments included half-face Melasma Area Severity Index (MASI), Overall Hyperpigmentation scale, and Melasma Severity Rating Scale (MSRS). Patients completed a Melasma Quality of Life (MelasQoL) questionnaire and clinical photographs were taken at each visit.

RESULTS

CTB and HQ 4% demonstrated statistically significant improvements in half-face MASI, Overall Hyperpigmentation, MSRS and MelasQol compared to baseline. HQ 4% showed statistically significant improvements in MSRS at week 12 compared to CTB, but was non-superior for all other clinical endpoints.

CONCLUSION

HQ-free, retinol-free CTB and HQ 4% both are effective and well-tolerated in the treatment of moderate facial melasma in FST III–VI. J Drugs Dermatol. 2020;19(9):822-827. doi:10.36849/JDD.2020.5353.

Fabrication, characterization and comparison of α-arbutin loaded dissolving and hydrogel forming microneedles

In this study, polyacrylic acid-co-maleic acid (PAMA) and polyvinyl alcohol (PVA) (1:4) were used to fabricate dissolving microneedles (DMNs) and hydrogel forming microneedles (HMNs) which incorporated α-arbutin. Αlpha-arbutin is commonly used as a skin lightening agent. However, it has poor penetration ability due to its hydrophilic properties. The purpose of this study was to compare the permeation of α-arbutin into the skin using DMNs and HMNs. Both types of microneedles (MNs) were sharp, strong with elegant appearance and approximately 100% penetrated the neonatal porcine skin. All needles of α-arbutin loaded DMNs were completely dissolved within 45 min, whereas maximum swelling of HMNs was observed at 4 h. In vitro permeation studies showed that α-arbutin loaded DMNs and HMNs provided significantly about 4.5 and 2.8 times, respectively, greater α-arbutin permeability than gel and commercial cream (P < 0.05). In vivo study also showed high intradermal delivery of α-arbutin levels using DMNs (5.33 µg/mL) and HMNs (1.47 µg/mL) when compared to that of commercial cream 0.15 µg/mL. Moreover, the micro-holes caused by applying MNs can reseal within 1 h. MNs were also stable at 25 °C for 3 months. The results suggested that DMNs and HMNs developed have a promising platform for transdermal delivery.

Therapeutic Insights in Melasma and Hyperpigmentation Management

Melasma and postinflammatory hyperpigmentation (PIH) are the most common forms of dyschromia in patients with skin of color. Both are associated with a high psychological burden of disease. To exacerbate this burden, the need for treatment is chronic, and the results are often suboptimal in the eyes of the patient. Successful treatment is therefore contingent upon a correct diagnosis, patient education, and a carefully considered therapeutic approach. The latter is often multimodal in its design, incorporating sun protection, topical and systemic medications, and in some cases, procedural intervention. Although topical hydroquinone is a mainstay of treatment for melasma and PIH, there are alternatives that have emerged as of late that have shown varying degrees of promise, both in terms of safety and efficacy. In this article, we review the epidemiological, clinical, and histologic features of melasma and postinflammatory hyperpigmentation, and discuss important considerations for both established and emerging treatments for these vexingly common and difficult to treat conditions.

In Vitro and In Vivo Efficacy and Tolerability of a Non-Hydroquinone, Multi-Action Skin Tone Correcting Cream

Background: Pigmentation disorders are therapeutically challenging to treat, requiring complicated regimens. Objectives: Alternatives to hydroquinone (HQ) are desired. We evaluated the efficacy and tolerability of a non-HQ multi-action skin tone corrector (ETCS) developed to inhibit melanin production and improve skin quality. Design and Methods: Twice-daily use of ETCS and ETCS + AHA-Ret, a retinoid-based alpha hydroxy acid cream, was evaluated in subjects with mild to severe dyschromia. Digital images were obtained at baseline, 4, 8, and 12 weeks and included assessment of dyschromia, erythema, fine lines/wrinkles, pores, texture, and global improvement. Melanin Index (MI) measurements were obtained at baseline, 4, 8, and 12 weeks. Subject self-assessments were obtained over the course of the study. Adverse Events (AEs) were collected throughout the study. An extension study evaluated use over 16-weeks. Results: Significant mean reductions from baseline occurred in dyschromia for ETCS (n=42) and ETCS + AHA-Ret (n=10) over 12 weeks (P<0.0001, each). Significant mean reductions from baseline in MI were achieved in both groups at every timepoint (ETCS: P<0.0001; ETCS + AHA-Ret: P<0.02, 4 weeks; P<0.0001, 8 and 12 weeks). Substantial improvements were demonstrated in global improvement, fine lines/wrinkles, erythema, pores, and texture at 12 weeks. Reductions from baseline occurred in dyschromia and MI (P<0.0001, each) at 16 weeks. High levels of subject satisfaction were reported with nearly all subjects reporting reduced appearance of uneven skin tone/discoloration and lightened darker patches, and improvement in overall skin tone. Mild, transient AEs were reported with no discontinuations due to an AE. Conclusions: Twice daily use of ETCS led to early, significant reductions in dyschromia and melanin index. Combination use with a retinoid-based, AHA cream in the evening demonstrated enhanced reductions. ETCS effectively reduced hyperpigmentation, improved overall skin appearance, and was highly tolerable. J Drugs Dermatol. 2019;18(7):642-648.

Whitening effect of L-ascorbate-2-phosphate trisodium salt on solar lentigos

Little is known about the anti-pigmenting effects of whitening agents on solar lentigos (SLs), which comprise ~ 60% of hyperpigmented facial lesions of Asian subjects. Lotions with or without 6% L-ascorbate-2-phosphate trisodium salt (APS) [test lotion (TL) and placebo lotion (PL), respectively] were applied twice daily for 24 weeks in a double-blind half-face study of 27 Japanese females with SLs on both sides of their faces. Pigmentation scores were evaluated using a photo-scale and the skin colors were assessed using a color difference meter and a mexameter for SLs and the non-lesional surrounding skin (NLS). Although the pigmentation scores were not significantly different between the TL and PL-treated SLs after 24 weeks, the L values of TL-treated SLs and NLS increased significantly with a significantly higher △L value in SLs than in NLS. In contrast, the L values of PL-treated SLs and NLS remained unchanged after the treatment. The number of subjects with > 2.0 △L was 7 of 27 (TL) and 0 of 27 (PL) in SLs and 3 of 27 (TL) and 0 of 27 (PS) in NLS. In contrast, the melanin index in TL-treated SLs and NLS significantly decreased with a significantly higher △melanin index in SLs than in NLS. Similarly, the melanin index of PL-treated SLs and NLS were significantly decreased with a significantly higher △melanin index in SLs than in NLS. These findings strongly indicate that APS has a weak but significant anti-pigmenting effect on SLs and a significant whitening effect even on normally pigmented healthy skin.

Brightening and Improvement of Facial Skin Quality in Healthy Female Subjects With Moderate Hyperpigmentation or Dark Spots and Moderate Facial Aging

Objective: To evaluate the safety and efficacy of ISDINCEUTICS Melaclear® serum (Barcelona, Spain) on skin brightness, skin quality, and signs of facial aging. Design: This was a single-center, observational, open label, prospective clinical study. Ten healthy females (ages 30-70) with moderate signs of facial aging and moderate photodamage (hyperpigmentation and/or sun spots) were enrolled. Treatment consisted of topical twice-daily application of Melaclear serum, morning and evening, to the face and neck for 12 weeks. Efficacy assessments were conducted at weeks 4, 8, and 12. Standardized photographs, expert investigator grading, tolerability assessments, and subjects reported outcome measures were performed at all visits. Adverse events (AEs) were monitored throughout. Visual assessments of the face and neck included grading for radiance, smoothness, pigmentation, erythema, pore size, skin clarity, skin brightness, skin tone, luminosity, skin complexion, photodamage, hyperpigmentation, wrinkle severity, pigment via the modified Melasma Area and Severity Index (MASI), and overall global aesthetic improvement (GAIS). Safety and tolerability assessments included an evaluation of face and neck for stinging/burning by the subject and dryness, scaling, edema, and erythema by the treating investigator at all study visits. Results: All enrolled subjects completed the study. At the 8 and 12-week follow up visit, there was a statistically significant improvement in the investigator GAIS (1.1 and 1.3, respectively) for the face from baseline. MASI scores were all statistically significantly reduced in the face from week 8 onward relative to baseline. In addition, all skin quality parameters assessed in the face significantly improved from baseline to week 12. Subject global aesthetic improvement scale scores (SGAIS) were also significantly improved at week twelve from baseline (1.8 change) as were skin quality assessments. The average rating for patient satisfaction was 2, or "satisfied" with the overall treatment effectiveness from week 4 onwards. For the neck none of the investigator or subject assessments improved significantly at any time point. No adverse events, tolerability events, or unexpected side effects were observed or reported for any of the subjects. Conclusion: Twice a day treatment of women with moderate facial photoaging and hyperpigmentation with Melaclear serum can significantly improve skin quality, reduce the severity and intensity of hyperpigmentation, and improve signs of photodamage within 12 weeks without any side effects. J Drugs Dermatol. 2018;17(12):1310-1315.

Approach to Skin Lightening in Patients With Melasma

I read with interest the informative article by Spencer et al1 that describes the efficacious use as a novel skin lightening agent (LumaPro-C) for the treatment of patients with melasma.

Inhibition of Human Tyrosinase Requires Molecular Motifs Distinctively Different from Mushroom Tyrosinase

Tyrosinase is the rate-limiting enzyme of melanin production and, accordingly, is the most prominent target for inhibiting hyperpigmentation. Numerous tyrosinase inhibitors have been identified, but most of those lack clinical efficacy because they were identified using mushroom tyrosinase as the target. Therefore, we used recombinant human tyrosinase to screen a library of 50,000 compounds and compared the active screening hits with well-known whitening ingredients. Hydroquinone and its derivative arbutin only weakly inhibited human tyrosinase with a half-maximal inhibitory concentration (IC₅₀) in the millimolar range, and kojic acid showed a weak efficacy (IC₅₀ > 500 μmol/L). The most potent inhibitors of human tyrosinase identified in this screen were resorcinyl-thiazole derivatives, especially the newly identified Thiamidol (Beiersdorf AG, Hamburg, Germany) (isobutylamido thiazolyl resorcinol), which had an IC₅₀ of 1.1 μmol/L. In contrast, Thiamidol only weakly inhibited mushroom tyrosinase (IC₅₀ = 108 μmol/L). In melanocyte cultures, Thiamidol strongly but reversibly inhibited melanin production (IC₅₀ = 0.9 μmol/L), whereas hydroquinone irreversibly inhibited melanogenesis (IC₅₀ = 16.3 μmol/L). Clinically, Thiamidol visibly reduced the appearance of age spots within 4 weeks, and after 12 weeks some age spots were indistinguishable from the normal adjacent skin. The full potential of Thiamidol to reduce hyperpigmentation of human skin needs to be explored in future studies.

Evidence for Anti-Aging South Korean Cosmeceuticals

<p>As the market for South Korean skin care products grows in the U.S. and worldwide, consumers will increasingly seek advice from dermatologists regarding their efficacy. In this paper, the evidence behind the anti-aging and skin whitening activity of ingredients in the most popular South Korean skin care products was reviewed and critically evaluated. Industry profit data from Euromonitor was obtained to identify the top cosmeceutical brands by retail value in South Korea. The top selling products and their ingredients were then identified from individual brand websites. A comprehensive literature search was conducted using Pubmed to identify and grade the anti-aging and whitening efficacy for nine popular ingredients: licorice, niacinamide, beta-glucan, snail mucus, ginkgo biloba, ginseng, green tea, pomegranate, and soy. Of the various ingredients reviewed, niacinamide, green tea, licorice, and soy have the most published data for anti-aging and whitening activity. Although the literature shows modest results, small sample sizes limit interpretation. High-level evidence to support the use of South Korean skin care products in anti-aging and skin whitening is lacking.</p> <p><em>J Drugs Dermatol. 2017;16(4):358-364.</em></p>.

Split-Face Comparison of an Advanced Non-Hydroquinone Lightening Solution to 4% Hydroquinone

INTRODUCTION

Hyperpigmentation is a primary concern for many cosmetic patients because of its high rate of occurrence and significant impact on perceived age. While 4% hydroquinone has been the gold-standard of treatment, there is a growing interest in non-hydroquinone solutions, however, many of these newer solutions fail to deliver equivalent improvement.

METHODS

This double-blind, randomized, split-face study compares the effects of a new OTC non-hydroquinone lightening product (JM) to an available 4% hydroquinone lightening solution (OB) on the appearance of hyperpigmentation, texture, and ne lines and wrinkles. Comparisons were determined by both physician assessment and subject self-assessment at baseline, 4, 8, and 12 weeks.

RESULTS

Physician assessment showed statistically equivalent improvement on both sides of the face with the JM side showing equivalent or superior average improvement in all assessed categories. Subject self-assessment showed a significant preference for the JM product over the 4% hydroquinone and a substantially higher perception of overall improvement over 4% hydroquinone (P=0.058).

DISCUSSION

Physician assessment showed equal or superior average improvement in all measured categories with no statistically significant difference between the two sides. Subject self-assessment, however, showed a significant and growing preference toward the investigated JM product over the course of the study. Overall, the results of this study show the JM product to be equivalent if not superior to 4% hydroquinone for results and patient satisfaction. J Drugs Dermatol. 2016;15(12):1571-1577.

Development and Clinical Assessment of a Comprehensive Product for Pigmentation Control in Multiple Ethnic Populations

BACKGROUND

Pigmentary changes in people of different ethnic origins are controlled by slight variations in key biological pathways leading to different outcomes from the same treatment. It is important to develop and test products for desired outcomes in varying ethnic populations.

OBJECTIVES

To develop a comprehensive product (LYT2) that affects all major biological pathways controlling pigmentation and test for clinical efficacy and safety in different ethnic populations.

METHODS

A thorough analysis of biological pathways was used to identify ingredient combinations for LYT2 that provided optimal melanin reduction in a 3-D skin model. Expression of four key genes for melanogenesis, TYR, TYRP-1, DCT, and MITF was analyzed by qPCR. Clinical study was conducted to compare the efficacy and tolerability of LYT2 against 4% hydroquinone (HQ).

RESULTS

Average melanin suppression by LYT2 in 7 independent experiments was 45%. All four key genes show significant down- regulation of expression. LYT2 provided statistically significant reductions in mean overall hyperpigmentation grades as early as week 2 compared to baseline, with continued significant improvements through week 12 in all ethnic groups tested.

CONCLUSION

We have successfully combined management of 6 categories of pathways related to melanogenesis: melanocyte activation, melanosome development, melanin production, melanin distribution, keratinocyte turnover, and barrier function to create a comprehensive HQ-free product. The outcome clearly shows greater pigmentation control with LYT2 compared to other HQ-free products in skin tissue models and earlier control in clinical studies compared to 4% HQ. Clinical study shows pigmentation control benefits of LYT2 in people of Caucasian, Hispanic, and African ethnic origins. J Drugs Dermatol. 2016;15(12):1562-1570.

Novel Anti-Melanogenesis Properties of Polydeoxyribonucleotide, a Popular Wound Healing Booster

Polydeoxyribonucleotide (PDRN), a deoxyribonucleotide polymer, is popularly used for faster healing of cutaneous wounds and boosting of neocollagenesis of photoaged skin among current dermatologic practitioners. Some patients receiving PDRN injection treatment also reported improvement of photoaging-associated mottled pigmentation (PMP). To investigate the effect of PDRN on cutaneous melanogenesis, we examined the effect of PDRN and an available product (Placentex^®) containing PDRN on melanogenesis using human melanocytes-keratinocytes cocultures and mouse melanocytes. Melanin content, tyrosinase activity, and levels of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related protein (TRP-1) were determined. Intracellular signaling pathways were assessed by Western blotting. PDRN and Placentex^® led to decreases in melanin content, tyrosinase activity, and MITF and TRP-1 expression with concomitant increases in phosphorylated forms of extracellular signal-regulated protein kinase (ERK) and AKT in mouse melanocytes. More importantly, both PDRN and Placentex^® significantly suppressed the melanin content in human melanocyte–keratinocyte cocultures. Clinical evaluation of six female patients with facial hyperpigmentation after three sessions of intradermal PDRN injections using a 5-point scale revealed that PDRN led to more than noticeable improvements in hyperpigmented lesions. This is the first study to demonstrate that PDRN, which is known for its wound-healing properties, may have novel anti-melanogenesis and potential skin whitening properties.

[Cutaneous depigmentation in black female population for cosmetic purposes: results of a KAP survey conducted in Abidjan (Ivory Coast)]

INTRODUCTION

Cutaneous depigmentation for cosmeticis purposes is a widespread practice among black African women. It has many complications that have been well documented for decades. However, the reasons of practitioners are not well known. The aim of our study was to understand the motivating reasons of these women in order to conduct a communication campaign for behavior change.

METHODS

We performed a cross-sectional KAP survey (Knowledge/Attitudes/Practices) at the Dermatology Department of the University Hospital of Treichville (Abidjan) Data were analyzed using Epi Info 3.5.1. and 6.04 software.

RESULTS

Practitioners were mostly young urban single, literate and professionally active women (20-40 years). Cutaneous depigmentation and its consequences were known to women, however, they thought that women with the lightest complexion were more attractive. They were influenced by media and friends. The most frequently observed complications were exogenous ochronosis and stretch marks. The local means of communication remained what essentially sustained the information needs of these women, because they help them to change their behavior.

CONCLUSION

The development of local communication strategies for behavior change seems necessary to stop the phenomenon of cutaneous depigmentation for cosmetic purposes in black female population in Abidjan.

Single blind, randomized, controlled trial of a lightening product with and without iontophoresis versus tretinoin and vehicle for hyperpigmentation

BACKGROUND

Hyperpigmentation is a common concern and has many causes including lentigines and melasma. Currently available topical products for hyperpigmentation are limited by their potential for irritation, lack of demonstrated efficacy or regulatory concerns.

OBJECTIVE

To compare the efficacy of a new skin lightening product with and without iontophoresis to a known effective product (tretinoin) and placebo on hyperpigmentation caused by lentigines and/or melasma. Secondary objectives included an assessment of the product's effects on the appearance of rhytides and roughness.

METHODS AND MATERIALS

Eighty subjects were randomized into one of four treatment groups: proprietary lightening product, proprietary lightening product with iontophoresis, tretinoin 0.05% cream, or vehicle control. Seventy-four subjects completed all study visits. Blinded assessments of subjects were performed at each visit under ambient and Wood's light.

RESULTS

The proprietary skin lightening product improved facial hyperpigmentation versus placebo under ambient light (P= 0.05) and Wood's lamp (P= 0.01) examination. Tretinoin also improved facial hyperpigmentation versus placebo under Wood's lamp (P= 0.01). The proprietary product was better tolerated than tretinoin, with fewer subject reported side effects.

CONCLUSION

The investigational product was effective and may be better tolerated than tretinoin cream.

Targeting melanocyte and melanoma stem cells by 8-hydroxy-2-dipropylaminotetralin

Monobenzyl ether of hydroquinone (MBEH) is cytotoxic towards melanocytes. Its treatment efficacy is limited by an inability to eradicate stem cells. By contrast, 8-hydroxy-N,N-dipropyl-2-aminotetralin (8-DPAT) affects melanocyte stem cell survival. MBEH and 8-DPAT were added to melanocytes and melanoma cells to compare cytotoxicity. Stem cell content among viable cells was determined by fluorocytometry using markers CD34, Pax3, and CD271. Immunostaining was used to identify stem cells in skin explants treated with MBEH or 8-DPAT ex vivo. Mice were exposed to MBEH or 8-DPAT and scanned for depigmentation before harvesting skin. MBEH exposure prompted a relative increase in stem cells among cultured melanocytes and melanoma cells, as treatment preferentially eliminated differentiated cells and spared the stem cells. Viability of this remaining, enriched stem cell population was however rapidly reduced by exposure to 8-DPAT within melanocyte and melanoma cell cultures. In human skin explants, the abundance of melanocyte stem cells was also visibly reduced after 8-DPAT treatment, in contrast to tissue exposed to MBEH. Meanwhile, significant depigmentation of the mouse pelage and loss of differentiated melanocytes was observed in vivo in response to topical application of MBEH, but not 8-DPAT. Prolonged application of the latter agent instead appeared to effectively reduce the abundance of melanocyte stem cells in the dermis. This furthers the idea that MBEH and 8-DPAT target complementary cell populations. Results indicate that combination treatment may demonstrate superior therapeutic activity by eliminating both differentiated and tumor initiating populations.

New and emerging treatments for hyperpigmentation

The treatment of disorders of hyperpigmentation including melasma, photoaging-related dyschromia, and postinflammatory hyperpigmentation pose numerous challenges, especially in patients with higher Fitzpatrick skin types (skin of color). Given limitations in efficacy as well as safety and cost considerations of available therapies, a "magic bullet" single treatment modality for hyperpigmentation is currently lacking. Successful treatment typically involves a combination of topical agents with or without in-office procedures, exploiting the different mechanisms of action of each agent or treatment modality. This article will review recently published studies involving newer topical and procedural approaches to this common dermatologic concern.

An evaluation of the benefits of a topical treatment in the improvement of photodamaged hands with age spots, freckles, and/or discolorations

BACKGROUND

Photoaging of the hands is common due to frequent exposure to environmental factors.

OBJECTIVE

To evaluate the efficacy of a topically applied cream formulated with an alpha-hydroxy acid, depigmenting agents, and antioxidants to improve the appearance of characteristics associated with photodamaged hands.

METHODS

This was a single-site, open-label study of a proprietary topical treatment (Vivité Vibrance Décolleté, Allergan, Inc.) in adult female subjects with moderate-to-severe photoaging of the hands. The treatment was administered to the hands twice daily over an 8-week period. Treatment efficacy was assessed at baseline and weeks 4 and 8 using the Investigator Global Assessment (IGA) score based on the percentage coverage and color depth of photodamaged areas. The severity of age spots, freckles, and hand skin discoloration were also assessed; digital and ultraviolet photography of the hands was performed. Subject-reported assessments of treatment efficacy were evaluated using a questionnaire administered at week 8. Statistical significance was defined with an α set at P≤.05.

RESULTS

Thirty-five subjects were enrolled with a mean age of 55.6 years; 33 subjects completed the study. The IGA of the appearance of hand photodamage improved from a mean (standard deviation) score of 5.0 (0.8) at baseline to 3.1 (1.5) and 2.6 (1.3) at weeks 4 and 8, respectively (1=mild; 9=severe). Based on expert-grader evaluation, subjects demonstrated statistically significant improvements from baseline in IGA at weeks 4 and 8 in age spots and freckling at weeks 4 and 8, (P<.0003) and in skin discolorations at week 8 (P<.05). The majority of subjects reported that they perceived improvements in each of the 9 parameters associated with skin appearance. No adverse events were reported.

CONCLUSIONS

The appearance of age-related hand pigmentation characteristics were significantly improved at 4 and 8 weeks of treatment. Subjects reported post-treatment improvements in other characteristics associated with healthy skin.

Minimal change disease caused by exposure to mercury-containing skin lightening cream: a report of 4 cases

Mercury is a known cause of nephrotic syndrome and the underlying renal pathology in most of the reported cases was membranous nephropathy. We describe here 4 cases of minimal change disease following exposure to mercury-containing skin lightening cream for 2 - 6 months. The mercury content of the facial creams was very high (7,420 - 30,000 parts per million). All patients were female and presented with nephrotic syndrome and heavy proteinuria (8.35 - 20.69 g/d). The blood and urine mercury levels were 26 - 129 nmol/l and 316 - 2,521 nmol/d, respectively. Renal biopsy revealed minimal change disease (MCD) in all patients. The use of cosmetic cream was stopped and chelation therapy with D-penicillamine was given. Two patients were also given steroids. The time for blood mercury level to normalize was 1 - 7 months, whereas it took longer for urine mercury level to normalize (9 - 16 months). All patients had complete remission of proteinuria and the time to normalization of proteinuria was 1 - 9 months. Mercury-containing skin lightening cream is hazardous because skin absorption of mercury can cause minimal change disease. The public should be warned of the danger of using such products. In patients presenting with nephrotic syndrome, a detailed history should be taken, including the use of skin lightening cream. With regard to renal pathology, apart from membranous nephropathy, minimal change disease should be included as another pathological entity caused by mercury exposure or intoxication.